1. Field of the Invention
This invention relates to a collapsible and adjustable steering column assembly.
2. Description of the Prior Art
One conventional form of a steering column assembly comprises two shaft sections one of which is axially adjustable relative to the other to allow the length of the steering column to be varied by the driver. These two sections are supported in a non-rotatable jacket which is attached to the vehicle body and which is movable with the adjustable shaft section. It has also been proposed to connect the jacket to the vehicle body by an element which deforms under impact loads to allow the steering column to collapse at a controlled rate so that the kinetic energy of impact is absorbed in a gradual movement of the column. Where such elements are incorporated in adjustable steering columns the connection between the deformable element and the vehicle body are slidable to accommodate the adjustment of the steering column.
In addition, deformable elements have been constructed to plastically stretch as well as compress. Two such extending deformable elements are disclosed in U.S. Pat. No. 3,475,984 issued to Ward on Apr. 10, 1969 and U.S. Pat. No. 3,597,994 issued to Shiomi on Aug. 10, 1971.